java.awt.Robot: hit助记键不工作

Question

我创建了一个简单的程序来使用awt。机器人按下ALT+F，它应该打开一个菜单项。但这行不通。一开始我以为是注意力问题。然后我添加了一个虚拟按钮来获得焦点，但id仍然不起作用。

请参阅代码

import java.awt.AWTException;
import java.awt.Robot;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.InputEvent;
import java.awt.event.KeyEvent;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
class MenuActionListener implements ActionListener {
    public void actionPerformed(ActionEvent actionEvent) {
        System.out.println("Selected: " + actionEvent.getActionCommand());
    }
}
public class MenuAction {
    public static void main(final String args[]) throws AWTException {
        ActionListener menuListener = new MenuActionListener();
        JFrame frame = new JFrame("MenuSample Example");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        JMenuBar menuBar = new JMenuBar();
        // File Menu, F - Mnemonic
        JMenu fileMenu = new JMenu("File");
        fileMenu.setMnemonic(KeyEvent.VK_F);
        menuBar.add(fileMenu);
        // File->New, N - Mnemonic
        JMenuItem newMenuItem = new JMenuItem("New", KeyEvent.VK_N);
        newMenuItem.addActionListener(menuListener);
        fileMenu.add(newMenuItem);
        frame.setJMenuBar(menuBar);
        frame.setSize(650, 650);
        JButton button = new JButton("Test");
        frame.getContentPane().add("South", button);
        frame.setBounds(100, 100, 400, 400);
        frame.setVisible(true);
        button.requestFocusInWindow();
        Robot robot = new Robot();
        robot.setAutoDelay(500);
        robot.waitForIdle();
        robot.keyPress(KeyEvent.ALT_MASK);
        robot.keyPress(KeyEvent.VK_F);
        robot.keyRelease(KeyEvent.VK_F);
        robot.keyRelease(KeyEvent.ALT_MASK);
        robot.waitForIdle();
    }
}

Answer 1

两件事，首先，你应该使用KeyEvent.VK_ALT而不是KeyEvent.ALT_MASK，第二，当你的Robot代码执行时，窗口可能不可见/活动，你需要等待，直到窗口已经可见，即使这样，你可能需要在将来的某个时候执行任务，以确保操作系统已经使窗口可见，例如…

import java.awt.AWTException;
import java.awt.Robot;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.InputEvent;
import java.awt.event.KeyEvent;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.awt.event.WindowListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.SwingUtilities;
public class MenuAction {
    public static void main(final String args[]) throws AWTException {
        ActionListener menuListener = new MenuActionListener();
        JFrame frame = new JFrame("MenuSample Example");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        JMenuBar menuBar = new JMenuBar();
        // File Menu, F - Mnemonic
        JMenu fileMenu = new JMenu("File");
        fileMenu.setMnemonic(KeyEvent.VK_F);
        menuBar.add(fileMenu);
        // File->New, N - Mnemonic
        JMenuItem newMenuItem = new JMenuItem("New", KeyEvent.VK_N);
        newMenuItem.addActionListener(menuListener);
        fileMenu.add(newMenuItem);
        frame.setJMenuBar(menuBar);
        frame.setSize(650, 650);
        JButton button = new JButton("Test");
        frame.getContentPane().add("South", button);
        frame.setBounds(100, 100, 400, 400);
        frame.addWindowListener(new WindowAdapter() {
            @Override
            public void windowOpened(WindowEvent e) {
                button.requestFocusInWindow();
                new Thread(new Runnable() {
                    @Override
                    public void run() {
                        try {
                            Robot robot = new Robot();
                            robot.setAutoDelay(500);
                            robot.waitForIdle();
                            robot.keyPress(KeyEvent.VK_ALT);
                            robot.keyPress(KeyEvent.VK_F);
                            robot.keyRelease(KeyEvent.VK_F);
                            robot.keyRelease(KeyEvent.VK_ALT);
                            robot.waitForIdle();
                        } catch (AWTException exp) {
                            exp.printStackTrace();
                        }
                    }
                }).start();
            }
        });
        frame.setVisible(true);
    }
    public static class MenuActionListener implements ActionListener {
        public void actionPerformed(ActionEvent actionEvent) {
            System.out.println("Selected: " + actionEvent.getActionCommand());
        }
    }
}